Trading Off the Greens

OK, so I've gone a little green with the cloth diapering... and it's going fairly well. I've had to use disposables on Baby Sister quite a few times because she keeps getting a rash... After doing all sorts of insane things with laundering - of which I will spare you the gory details - we finally figured out it was a reaction to strawberries! She's not allergic, but she just can't have too many otherwise she'll get a horrendous diaper rash... crazy. But glad to have figured it out.
But now... Lazy Baby is all out refusing to nurse except for in the middle of the night. It's been a constant battle to get him to nurse. He's distracted by everything and just doesn't want to sit still. So, what I'm saving in disposable diapers I am now spending on formula :( Wondering how close to 1yr they have to be before starting regular milk... I know Doctors will say not before the day they turn one year... but ugghhhh! It's so typical of my life ;) saving in one area only to be spending more in another...